A harmonic reducer and driver

Abstract

The present invention provides a harmonic reducer, including a flexible wheel, a wave generator assembly and an output assembly, wherein the output assembly includes an output connector, the output connector includes a friction ring portion and an output disc portion, and the output disc portion is arranged on one side of the friction ring portion; the flexible wheel is arranged on the friction ring portion; the wave generator assembly is arranged inside the friction ring portion and abuts against the friction ring portion; the wave generator assembly squeezes the friction ring portion and the flexible wheel to produce synchronous deformation. The present invention also provides a driver. The harmonic reducer and driver provided by the present invention are provided with a friction ring portion made of a highly elastic and highly wear-resistant material between the roller and the flexible wheel, which can increase the service life and compensate for the influence caused by the tooth shape processing error, reduce the processing difficulty, and reduce the transmission noise. At the same time, the flexible wheel can be made of a material with higher rigidity, so that the outer teeth of the flexible wheel have higher pressure resistance, thereby improving the transmission efficiency and load capacity of the harmonic reducer.

Description

Technical Field

[0001] The present invention relates to the field of robotics technology, and in particular to a harmonic reducer and a driver. Background Art

[0002] At present, most of the key joints of robots use harmonic reducers. Compared with other reducers, under the same speed ratio and the same load, harmonic reducers have smooth transmission, the highest precision, small structure volume, and light weight. They are widely used in precision industries such as robots, CNC machine tools, and semiconductor equipment. Harmonic reducers generally include fixed wheels, flexible wheels, and wave generators containing flexible bearings. Torque output is transmitted through thin-walled deformable flexible wheels; the flexible wheels are usually cup-shaped or top-hat-shaped, with thin walls and a right angle portion close to 90 degrees. The flexible wheel of this structure has high requirements on the performance of steel. It is necessary to ensure the elasticity requirements while ensuring its hardness. Generally, imported alloy steel is used, and the processing accuracy requirements are relatively high. Due to its special materials and high production process requirements, its cost and price are much higher than other types of reducers. The complex manufacturing process of harmonic reducers leads to its high cost, which has become one of the obstacles to the popularization and application of robots.

[0003] At present, there is a way in the prior art to separate the cup-shaped or top-hat-shaped flexible wheel, which reduces the difficulty of processing by providing a cylindrical flexible wheel and output disc; in addition, since there is no traditional 90-degree thin-wall structure, stress concentration is eliminated, load capacity is increased, and fatigue life is improved. However, the above harmonic reducer still has problems such as complex structure, difficulty in assembling the flexible wheel and output disc, low transmission efficiency and service life. Summary of the invention

[0004] In order to solve at least one of the above technical problems, the purpose of the present invention is to provide a harmonic reducer and driver with simple structure, convenient assembly, high transmission efficiency, long service life and large output torque. At the same time, the harmonic reducer and driver have low cost and are easy to mass produce and apply.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A harmonic reducer is provided, comprising a flexspline, a wave generator assembly and an output assembly, wherein the output assembly comprises an output connector, the output connector comprises a friction ring portion and an output disc portion, the output disc portion is arranged on one side of the friction ring portion; the flexspline is arranged on the friction ring portion; the wave generator assembly is arranged inside the friction ring portion and abuts against the friction ring portion; the wave generator assembly squeezes the friction ring portion and the flexspline to generate synchronous deformation.

[0007] Furthermore, the flexible wheel comprises a meshing portion and a shifting post; the meshing portion is cylindrical and is provided with external teeth; and the shifting post is provided on one side end surface of the meshing portion.

[0008] Furthermore, the friction ring portion is a thin-walled cylinder, and the meshing portion is sleeved on the thin-walled cylinder; the output disc portion is a disc, and a shifting post hole is provided on the disc, and the shifting post is arranged in the shifting post hole.

[0009] Furthermore, the pin can only move relative to the pin hole along the radial direction of the disk.

[0010] Furthermore, the output component also includes an output shaft, a spline block is provided on the output shaft, and a spline hole is provided on the disc; the spline hole is cooperatively connected with the spline block.

[0011] Furthermore, it also includes a fixed wheel, which is in a circular ring shape, and an inner circumferential surface of the fixed wheel is provided with internal teeth, and the internal teeth are meshed with the external teeth.

[0012] Furthermore, it also includes a shell assembly, which includes a bottom shell and a shell cover; the fixed wheel is arranged between the bottom shell and the shell cover; the bottom shell, the fixed wheel and the shell cover are connected through screws.

[0013] Furthermore, the material elasticity of the friction ring portion is greater than the material elasticity of the meshing portion.

[0014] Furthermore, the material of the friction ring portion is rubber or TPU or TPV with built-in tire cords and / or steel wires; the material of the meshing portion is alloy or POM or HDPE.

[0015] The present invention also provides a driver, comprising a motor and the above-mentioned harmonic reducer, wherein the harmonic reducer is installed at the output end of the motor.

[0016] Compared with the prior art, the harmonic reducer and driver provided by the present invention have the following beneficial effects: the harmonic reducer provided by the present application has a friction ring portion between the roller and the flexible wheel, and the material elasticity of the friction ring portion is greater than the material elasticity of the flexible wheel. Compared with the prior art, the flexible wheel can be made of a material with higher rigidity, thereby greatly improving the pressure resistance of the external teeth on the flexible wheel, and correspondingly greatly improving the transmission efficiency and load capacity of the harmonic reducer.

[0017] The output connector is manufactured by integrating the friction ring and the output disc. The friction ring is made of a thin-walled ring with a highly elastic material, which is easy to produce harmonic deformation; the output disc has a certain thickness and can withstand a large load torque. Since the transmission between the flexible wheel and the output disc is achieved through the cooperation of the lever and the lever hole, the stress concentration at the connection between the friction ring and the output disc is reduced, and the strength requirements and processing difficulty are reduced.

[0018] The high wear resistance of the friction ring can reduce the impact of roller friction and increase the service life of the harmonic reducer; the high elasticity of the friction ring makes it have a buffering effect. The roller squeezes the meshing part onto the fixed wheel through the highly elastic friction ring, which can compensate for the impact of tooth profile processing errors, reduce processing difficulty, and reduce noise.

[0019] The output connector and the output shaft are connected by spline, which can realize zero-backlash transmission and does not require other connectors. It is easy to install and greatly simplifies the structure of the harmonic reducer.

[0020] The harmonic reducer provided in the present application is installed by connecting the bottom shell, the stator and the shell cover through screws, which has a simple structure, is easy to install and reduces costs.

[0021] In summary, the present invention provides a harmonic reducer and driver with high transmission efficiency, long service life and simple structure, which has broad application prospects in the field of robots. At the same time, the harmonic reducer and driver are easy to manufacture, low in cost, and convenient for large-scale production and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The overall structure of a driver with a harmonic reducer according to a specific embodiment of the present invention is schematically shown;

[0023] Figure 2 An exploded view of a driver with a harmonic reducer according to a specific embodiment of the present invention is schematically shown;

[0024] Figure 3 The internal structure of a driver with a harmonic reducer according to a specific embodiment of the present invention is schematically shown;

[0025] Figure 4 The schematic diagram of the structure of a flexible wheel according to a specific embodiment of the present invention is shown;

[0026] Figure 5 A schematic diagram of the structure of an output connector according to a specific embodiment of the present invention is shown;

[0027] Figure 6 A schematic diagram of the structure of an output connector according to a specific embodiment of the present invention from another perspective is shown;

[0028] Figure 7 A schematic diagram of the structure of an output shaft according to a specific embodiment of the present invention is shown;

[0029] Figure 8 A partial structural diagram of a harmonic reducer according to a specific embodiment of the present invention is schematically shown;

[0030] Fig. 9 A schematic diagram of a partial structure of a harmonic reducer from another perspective according to a specific embodiment of the present invention is shown;

[0031] Fig.10 The figure schematically shows the matching diagram of the flexible wheel and the output connecting member according to a specific embodiment of the present invention.

[0032] The reference numerals are described as follows:

[0033] 1 motor, 2 bottom shell, 3 fixed wheel, 4 shell cover, 4-1 bearing, 5 wave generator assembly, 5-1 support frame, 5-2 roller, 6 flexible wheel, 6-1 meshing part, 6-2 shifting column, 7 output assembly, 7-1 output connecting piece, 7-11 friction ring part, 7-12 output disc part, 7-121 spline hole, 7-2 output shaft, 7-21 spline block. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with specific embodiments. Please note that the embodiments described below are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in the art or the product instructions shall be followed.

[0035] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] The harmonic reducer and the driver of the present invention will be described in detail below through specific embodiments: Figure 1-10 As shown, the driver described in this embodiment includes a motor 1 and a harmonic reducer.

[0038] The specific structure of the harmonic reducer provided in this embodiment is as follows:

[0039] The harmonic reducer includes components such as a housing assembly, a wave generator assembly 5, a flexible wheel 6, and an output assembly 7. The housing assembly includes a bottom housing 2 and a housing cover 4. The bottom housing 2 is provided with a fixing hole and a connecting hole; screws can be used to fix the bottom housing 2 on the output end of the motor 1 through the fixing hole. The housing cover 4 is provided with a threaded hole opposite to the connecting hole; screws are used to connect and install the bottom housing 2 and the housing cover 4 through the connecting hole and the threaded hole.

[0040] The fixed wheel 3 is in a circular ring shape, and internal teeth are arranged on its inner circumference. The fixed wheel 3 is arranged between the bottom shell 2 and the shell cover 4, and a through hole corresponding to the connection hole is arranged on the fixed wheel 3 for screws to pass through, that is, the bottom shell 2, the fixed wheel 3 and the shell cover 4 are connected as a whole by screws in sequence, and an installation cavity is formed inside the three, and the installation cavity provides installation space for the internal parts of the harmonic reducer.

[0041] Components such as the wave generator assembly 5, the flexible wheel 6 and the output assembly 7 are arranged in the installation cavity. The wave generator assembly 5 includes a support frame 5-1 and a roller 5-2; the roller 5-2 is arranged at both ends of the support frame 5-1, can rotate with the support frame 5-1, and can rotate freely relative to the support frame 5-1. A motor shaft hole is arranged at the center of the support frame 5-1, and the support frame 5-1 is fixed to the motor output shaft of the motor 1 through the motor shaft hole, and is actuated to rotate by the motor output shaft.

[0042] The flexible wheel 6 includes a meshing portion 6-1 and a shifting post 6-2. The meshing portion 6-1 is a deformable cylindrical surface with a certain number of teeth on the outer circumference; the outer circumference of the meshing portion 6-1 is provided with outer teeth extending along the axial direction and in a circumferential ring shape and evenly spaced. A plurality of shifting posts 6-2 are evenly spaced and distributed on one side end surface of the meshing portion 6-1 in a circular distribution. The flexible wheel 6 is made of an elastic material with high pressure resistance and high wear resistance, preferably an alloy, POM or HDPE.

[0043] The output assembly 7 includes an output connector 7-1 and an output shaft 7-2. The output connector 7-1 is an integrated structure consisting of a friction ring portion 7-11 and an output disc portion 7-12. The friction ring portion 7-11 is a thin-walled cylinder made of an elastic material with high wear resistance. The elasticity of the material of the friction ring portion 7-11 is greater than the elasticity of the material of the flexible wheel 6, and is preferably rubber or TPU or TPV with built-in tire cords and / or steel wires. The inner circumferential surface of the friction ring portion 7-11 is a smooth surface, and the roller 5-2 abuts on the inner circumferential surface of the friction ring portion 7-11. The output disc portion 7-12 is a disc, on which a lever hole corresponding to the lever 6-2 is provided. The flexible wheel 6 is installed in cooperation with the output connecting piece 7-1, the meshing portion 6-1 is sleeved on the friction ring portion 7-11, and the two are fixedly connected by interference fit; the shifting post 6-2 is inserted into the shifting post hole, and the shifting post 6-2 can only move relative to the output disk portion 7-12 along the radial direction of the output disk portion 7-12 under the restriction of the shifting post hole, that is, the shifting post 6-2 can drive the output disk portion 7-12 to rotate.

[0044] The number of external teeth on the flexible wheel 6 is less than that of the internal teeth on the fixed wheel 3; the tooth shapes of the internal teeth and the external teeth are the same, and the two can mesh and transmit. Since the number of teeth on the internal teeth on the fixed wheel 3 is greater than the number of teeth on the external teeth on the flexible wheel 6, when the two are coaxially arranged without external force, the maximum outer diameter of the flexible wheel 6 is smaller than the minimum inner diameter of the fixed wheel 3, and the two are not in contact. After the wave generator assembly 5 is installed in the friction ring part 7-11, the roller 5-2 on the wave generator assembly 5 squeezes the friction ring part 7-11 and the meshing part 6-1 to deform into an ellipse, so that the external teeth of the ellipse-shaped flexible wheel 6 in the long axis direction mesh with the internal teeth of the fixed wheel 3; there is a certain gap between the ellipse-shaped flexible wheel 6 and the fixed wheel 3 in the short axis direction; the two-point contact meshing state of the flexible wheel 6 and the fixed wheel 3 is formed; accordingly, the shifting post 6-2 moves in the shifting post hole, and the whole presents an ellipse with the meshing part 6-1.

[0045] The output disc 7-12 is also provided with a spline hole 7-121. The output shaft 7-2 is provided with a spline block 7-21 that matches the shape of the spline hole 7-121. The spline block 7-21 is inserted into the spline hole 7-121, so that the output connector 7-1 can drive the output shaft 7-2 to rotate integrally. The output shaft 6-2 is rotatably supported on the housing cover 4 through the bearing 4-1, and extends out of the housing cover 4, serving as the output end of the entire harmonic reducer.

[0046] The working principles of the harmonic reducer and driver provided by the present invention are described in detail as follows:

[0047] In the harmonic reducer, the fixed wheel 3, the flexible wheel 6 and the output assembly 7 are coaxially arranged. The meshing portion 6-1 and the friction ring portion 7-11 are deformed into an elliptical shape under the support of the wave generator assembly 5, and are in two-point contact meshing with the fixed wheel 3; wherein the roller 5-2 in the wave generator assembly 5 abuts against the friction ring portion 7-11, and the meshing portion 6-1 of the flexible wheel 6 meshes with the fixed wheel 3.

[0048] When the wave generator assembly 4 rotates continuously under the actuation of the motor 1, the meshing portion 6-1 and the friction ring portion 7-11 are squeezed by the roller 5-2 to produce synchronous periodic elliptical deformation, and the meshing point between the meshing portion 5-1 and the fixed wheel 3 is constantly changing. Since the number of teeth of the meshing portion 6-1 is less than the number of teeth of the fixed wheel 3, the flexible wheel 6 rotates relative to the fixed wheel 3 in the opposite direction of the rotation of the wave generator assembly 5. When the wave generator assembly 5 rotates one circle, the flexible wheel 6 rotates in the opposite direction by a certain angle.

[0049] Since the shape of the shifting post 6-2 of the flexible wheel 6 is adapted and can be radially slidably inserted into the shifting post hole of the output disk part 7-12, when the meshing part 6-1 is deformed into an elliptical shape, the shifting post 6-2 slides radially relative to the shifting post hole along the output disk part 7-12 under the actuation of the meshing part 6-1, and the distribution of the shifting post 6-2 also changes to an elliptical shape correspondingly with the meshing part 6-1. When the meshing point between the meshing part 6-1 and the fixed wheel 6-1 is constantly changing, the shifting post 6-2 continues to slide radially relative to the shifting post hole and deforms into a corresponding elliptical distribution state; at the same time, the shifting post 6-2 rotates with the meshing part 6-1 and actuates the output disk part 7-12 to rotate in the same direction and at the same angle. The output disk part 7-12 drives the output shaft 7-2 connected together by a spline method to obtain a reverse speed reduction output relative to the motor output shaft.

[0050] During the transmission process, the shifting post 6-2 slides radially relative to the shifting post hole along the output disk portion 7-12. Since the shifting post 6-2 produces its own small elliptical trajectory motion relative to the housing assembly, the shifting post 6-2 squeezes the side wall of the shifting post hole during the transmission process, driving the output disk portion 7-12 to rotate.

[0051] Compared with the prior art, the harmonic reducer provided by the present application has a friction ring portion between the roller and the flexible wheel, and the material elasticity of the friction ring portion is greater than the material elasticity of the flexible wheel. Compared with the prior art, the rigidity of the flexible wheel can be improved, thereby greatly improving the pressure resistance of the external teeth on the flexible wheel, and correspondingly greatly improving the transmission efficiency and load capacity of the harmonic reducer.

[0052] The output connector is manufactured by integrating the friction ring and the output disc. The friction ring is made of a thin-walled ring with a highly elastic material, which is easy to produce harmonic deformation; the output disc has a certain thickness and can withstand a large load torque. Since the transmission between the flexible wheel and the output disc is achieved through the cooperation of the lever and the lever hole, the stress concentration at the connection between the friction ring and the output disc is reduced, and the strength requirements and processing difficulty are reduced.

[0053] The high wear resistance of the friction ring can reduce the impact of roller friction and increase the service life of the harmonic reducer; the high elasticity of the friction ring makes it have a buffering effect. The roller squeezes the meshing part onto the fixed wheel through the highly elastic friction ring, which can compensate for the impact of tooth profile processing errors, reduce processing difficulty, and reduce noise.

[0054] The output connector and the output shaft are connected by spline, which can realize zero-backlash transmission and does not require other connectors. It is easy to install and greatly simplifies the structure of the harmonic reducer.

[0055] The harmonic reducer provided in the present application is installed by connecting the bottom shell, the stator and the shell cover through screws, which has a simple structure, is easy to install and reduces costs.

[0056] In summary, the present invention provides a harmonic reducer and driver with high transmission efficiency, long service life and simple structure, which has broad application prospects in the field of robotics.

[0057] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0058] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and assemble different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

Claims

1. A harmonic reducer, comprising a flexible wheel, a wave generator assembly and an output assembly, characterized in that: The output assembly includes an output connector, the output connector includes a friction ring portion and an output disc portion, the output disc portion is arranged on one side of the friction ring portion; the flexible wheel is arranged on the friction ring portion; the wave generator assembly is arranged inside the friction ring portion and abuts against the friction ring portion; the wave generator assembly squeezes the friction ring portion and the flexible wheel to generate synchronous deformation; The flexible wheel comprises a meshing portion and a shifting post; the meshing portion is cylindrical and is provided with external teeth; the shifting post is provided on one side end surface of the meshing portion; The friction ring part is a thin-walled cylinder, and the meshing part is sleeved on the thin-walled cylinder; the output disc part is a disc, and a lever hole is provided on the disc, and the lever is provided in the lever hole; The material elasticity of the friction ring portion is greater than the material elasticity of the meshing portion; The wave generator assembly comprises a support frame and rollers; the rollers are arranged at both ends of the support frame.

2. The harmonic reducer according to claim 1, characterized in that: The pin can only move relative to the pin hole along the radial direction of the disk.

3. The harmonic reducer according to claim 2, characterized in that: The output assembly further comprises an output shaft, a spline block is arranged on the output shaft, and a spline hole is arranged on the disc; the spline hole is cooperatively connected with the spline block.

4. The harmonic reducer according to claim 3, characterized in that: It also includes a fixed wheel, which is in a circular ring shape. The inner circumferential surface of the fixed wheel is provided with internal teeth, and the internal teeth are meshed with the external teeth.

5. The harmonic reducer according to claim 4, characterized in that: It also includes a shell assembly, which includes a bottom shell and a shell cover; the fixed wheel is arranged between the bottom shell and the shell cover; the bottom shell, the fixed wheel and the shell cover are connected through screws.

6. The harmonic reducer according to claim 5, characterized in that: The material of the friction ring part is rubber or TPU or TPV with built-in tire cord and / or steel wire; the material of the meshing part is alloy or POM or HDPE.

7. A driver, comprising a motor and a harmonic reducer according to any one of claims 1 to 6, characterized in that: The harmonic reducer is installed at the output end of the motor.

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